Conventional water dispensers can be divided into two types by different temperature ranges: hot/warm and hot/warm/cold. The operating principle is to directly or indirectly heat a hot-water storage tank and cool a cold-water storage tank to obtain the constant temperature of water, while the warm water is generated by mixing the hot water and the cold water.
For example, FIGS. 1 and 2 of the Taiwan Patent No. 1294510 disclose a technique for obtaining the hot water by heating directly with a heating tube within the hot-water tank and indirectly with a heater outside the hot-water tank respectively. In addition, FIG. 2 of the Taiwan Patent No. M285680 discloses a technique for obtaining the cold water by a compressor connected to the cold-water tank. However, there is a limitation of heating efficiency on the direct and indirect heating method with the heating tube and the heater, because the heating area is limited to a single point or a portion. Next, the cooling operation implemented in the dispenser with the compressor would contain disadvantages of large volume, refrigerant contamination and excess energy consumption indirectly.
Thermoelectric technologies have been applied for cooling and heating via charge carrier movement without any mechanical motion. Recently, the design of using a thermoelectric chip to provide the dispenser with cooling and heating operation becomes gradually popular in the market place. As shown in FIG. 1, a dispenser 1 for cooling operation with a thermoelectric chip is shown. The cold side 10c of the thermoelectric chip 10 is attached to the cold tank 11 for cooling the fluid therein. The hot side 10h of the thermoelectric chip 10 is provided with a heat sink 12 and a fan 13, in order to exchange the heat from the hot side 10h of the thermoelectric chip 10 to environment by the heat sink 12 and the fan 13.
In general, the dispenser for cooling/heating operation by a thermoelectric chip has advantages of a more stable condition and lower maintenance. In a conventional water dispenser system, the redundant heat exchanges from the hot side 10h to environment and consumes most of valuable heat energy. Moreover, the vibration and noise generated by the compressor and fan 13 during operation are big issues on household appliances. In addition, the current cooling/heating method of attracting the cooling/heating energy of the thermoelectric chip to the tank is not efficiently. Hence, a water dispenser system design for cooling/heating with the thermoelectric chip should be improved.